Raspbian 2 player chess game

JonB

@Quantum1982
a. Debug your code. That's what developers do when things go wrong.
b. Deal with the warnings I see in the output window.

Quantum1982

My debugger doesn't load ?

JonB

@Quantum1982
a. So sort out your debugger. And if you cannot do that yourself we need more than "My debugger doesn't load". Any error messages? How do you know it does not load?

b. I didn't say you had to use the actual debugger. It's a luxury you should get working, but it's not a requirement for your issue(s). You could do lots of work yourself just by putting in judicious qDebug() statements. And by taking heed of my earlier suggestion to check return results and use Q_ASSERTs. So far your coding is progressing but you need to add such techniques. And it's not just that they solve issues, they also help you to understand what is going on, making future coding better. In the case of the QGraphicsScene::addItme warnings you don't even need any of this, just looking at your code should tell you.

Quantum1982

Ok.

I get the following error : Unable to create a debugging engine.

Also, is there a property in the QGraphicsView that I need to set to stop the last column and row from stretching to fit the output size ?

Quantum1982

I am now implementing the mouse clocking by the user.
I have this so far :

class MyGraphicsPixmapItem : public QGraphicsPixmapItem
{
public:
int SelectedSquareX, SelectedSquareY;
void mousePressEvent(QMouseEvent *eventPress);
};

What I am doing is I am getting the position of the mouse cursor when the user elft clicks, then I am storing the board coordinates in SelectedSquareX and SelectedSquareY.

But how should I declare the constructor ?

jsulm

@Quantum1982 said in Raspbian 2 player chess game:

But how should I declare the constructor ?

Like https://doc.qt.io/qt-5/qgraphicspixmapitem.html does maybe?

Quantum1982

Ok I will look into that.
Concerning the drawn chessboard I have the following :

As you can see the last column and row are being stretched to fir the graphicsview area.
Is there a setting that I need to configure that willl stop this ?

Quantum1982

Ok
I have made some progress.
This is what I have so far :

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#endif // MAINWINDOW_H

#define BOARD_X1 20
#define BOARD_Y1 20
#define SQUARE_WIDTH 50
#define SQUARE_HEIGHT 50

#define WHITE_PAWN 0
#define WHITE_ROOK 1
#define WHITE_KNIGHT 2
#define WHITE_BISHOP 3
#define WHITE_QUEEN 4
#define WHITE_KING 5

#define BLACK_PAWN 6
#define BLACK_ROOK 7
#define BLACK_KNIGHT 8
#define BLACK_BISHOP 9
#define BLACK_QUEEN 10
#define BLACK_KING 11

#include <QMainWindow>
#include <QGraphicsView>
#include <QGraphicsItem>
#include <QLabel>
#include <QMouseEvent>

class CChessBoard : public QGraphicsView
{
public:

};

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE



class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    QLabel *WhiteQueen;
    QString ChessPieces[12];

    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
    QGraphicsScene *scene;
    QGraphicsRectItem *rectangle;

    int ChessPieceIndexes[8][8]; // indexes to the image url
    void LoadPieceGraphics(void);
    void SetStartPosition(void);
};



class MyGraphicsPixmapItem : public QGraphicsPixmapItem
{
   public:
    int SelectedSquareX, SelectedSquareY;
    MyGraphicsPixmapItem(QGraphicsItem *parent = nullptr);
    void mousePressEvent(QMouseEvent *eventPress);
};

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QImage>
#include <QLabel>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    scene = new QGraphicsScene(this);
    ui->graphicsView->setScene(scene);

   // MyGraphicsPixmapItem UserInput = MyGraphicsPixmapItem(QGraphicsItem *parent= nullptr);

    /* ///////////////////////////////////////////DRAW THE BOARD //////////////////////////////////////////////*/
    QBrush greenBrush(Qt::green);
    QBrush blueBrush(Qt::blue);
    QPen outlinePen(Qt::black);
    outlinePen.setWidth(2);

    for (int i=0;i<8;i++)
        for (int j=0;j<8;j++)
            if ((i+j)%2==0)
            rectangle = scene->addRect(BOARD_X1+(i*SQUARE_WIDTH),BOARD_Y1+(j*SQUARE_HEIGHT)
                                       ,BOARD_X1+(i*SQUARE_WIDTH)+SQUARE_WIDTH ,
                                       BOARD_Y1+(j*SQUARE_HEIGHT)+SQUARE_HEIGHT, outlinePen, blueBrush);
            else rectangle = scene->addRect(BOARD_X1+(i*SQUARE_WIDTH),BOARD_Y1+(j*SQUARE_HEIGHT)
                                            ,BOARD_X1+(i*SQUARE_WIDTH)+SQUARE_WIDTH ,
                                            BOARD_Y1+(j*SQUARE_HEIGHT)+SQUARE_HEIGHT, outlinePen, greenBrush);
   /* ///////////////////////////////////////////DRAW THE BOARD //////////////////////////////////////////////*/

    LoadPieceGraphics();
    SetStartPosition();

    /*
    WhiteQueen = new QLabel(this);
    QPixmap Pixmap(ChessPieces[4]); // White Queen

    WhiteQueen->setGeometry(BOARD_X1+4*SQUARE_WIDTH,BOARD_Y1+4*SQUARE_HEIGHT,
                            BOARD_X1+4*SQUARE_WIDTH+SQUARE_WIDTH,BOARD_Y1+4*SQUARE_HEIGHT+SQUARE_HEIGHT);
    WhiteQueen->setPixmap(Pixmap);
    WhiteQueen->setStyleSheet("background-color:rgba(0,0,255,0)");

    QLabel *BlackQueen = new QLabel(this);
    Pixmap.load(ChessPieces[10]); // Black Queen
    BlackQueen->setGeometry(BOARD_X1+4*SQUARE_WIDTH,BOARD_Y1+1*SQUARE_HEIGHT,
                            BOARD_X1+4*SQUARE_WIDTH+SQUARE_WIDTH,BOARD_Y1+1*SQUARE_HEIGHT+SQUARE_HEIGHT);
    BlackQueen->setPixmap(Pixmap);
    */

    QPixmap Pixmap(ChessPieces[0]); // White Pawn

    Pixmap.load(ChessPieces[0]);
    for (int i=0;i<8;i++)
    {
        QGraphicsPixmapItem* item = new QGraphicsPixmapItem(Pixmap);
        item->setPos(BOARD_X1+(i*SQUARE_WIDTH),BOARD_Y1+(7*SQUARE_HEIGHT));
        scene->addItem(item);
    }
    Pixmap.load(ChessPieces[1]);
    for (int i=0;i<8;i++)
    {
        QGraphicsPixmapItem* item = new QGraphicsPixmapItem(Pixmap);
        item->setPos(BOARD_X1+(i*SQUARE_WIDTH),BOARD_Y1+(8*SQUARE_HEIGHT));
        scene->addItem(item);
    }

    // White Rooks
    Pixmap.load(ChessPieces[1]);
    QGraphicsPixmapItem* item = new QGraphicsPixmapItem(Pixmap);
    item->setPos(BOARD_X1+(0*SQUARE_WIDTH),BOARD_Y1+(8*SQUARE_HEIGHT));
    scene->addItem(item);

    Pixmap.load(ChessPieces[1]);
    //QGraphicsPixmapItem* item = new QGraphicsPixmapItem(Pixmap);
    item->setPos(BOARD_X1+(7*SQUARE_WIDTH),BOARD_Y1+(8*SQUARE_HEIGHT));
    scene->addItem(item);

    // White Knights
    Pixmap.load(ChessPieces[2]);
    item->setPixmap(Pixmap);
    item->setPos(BOARD_X1+(1*SQUARE_WIDTH),BOARD_Y1+(8*SQUARE_HEIGHT));
    scene->addItem(item);

    item->setPos(BOARD_X1+(6*SQUARE_WIDTH),BOARD_Y1+(8*SQUARE_HEIGHT));
    scene->addItem(item);


    Pixmap.load(ChessPieces[6]); // Black Pawn
    for (int i=0;i<8;i++)
    {
        QGraphicsPixmapItem* item = new QGraphicsPixmapItem(Pixmap);
        item->setPos(BOARD_X1+(i*SQUARE_WIDTH),BOARD_Y1+(1*SQUARE_HEIGHT));
        scene->addItem(item);
    }

    Pixmap.load(ChessPieces[7]); // Black Rook
    item->setPixmap(Pixmap);
    item->setPos(BOARD_X1+(0*SQUARE_WIDTH),BOARD_Y1+(0*SQUARE_HEIGHT));
    scene->addItem(item);

    item->setPixmap(Pixmap);
    item->setPos(BOARD_X1+(7*SQUARE_WIDTH),BOARD_Y1+(0*SQUARE_HEIGHT));
    scene->addItem(item);

    Pixmap.load(ChessPieces[8]); // Black Knight
    item->setPixmap(Pixmap);
    item->setPos(BOARD_X1+(1*SQUARE_WIDTH),BOARD_Y1+(0*SQUARE_HEIGHT));
    scene->addItem(item);

    Pixmap.load(ChessPieces[9]); // Black Bishop
    item->setPixmap(Pixmap);
    item->setPos(BOARD_X1+(2*SQUARE_WIDTH),BOARD_Y1+(0*SQUARE_HEIGHT));
    scene->addItem(item);


}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::LoadPieceGraphics(void)
{
    ChessPieces[0] = "C:/Users/User/Desktop/WhitePawn.jpg";
    ChessPieces[1] = "C:/Users/User/Desktop/WhiteRook.jpg";
    ChessPieces[2] = "C:/Users/User/Desktop/WhiteKnight.jpg";
    ChessPieces[3] = "C:/Users/User/Desktop/WhiteBishop.jpg";
    ChessPieces[4] = "C:/Users/User/Desktop/WhiteQueen.jpg";
    ChessPieces[5] = "C:/Users/User/Desktop/WhiteKing.jpg";
    ChessPieces[6] = "C:/Users/User/Desktop/BlackPawn.jpg";
    ChessPieces[7] = "C:/Users/User/Desktop/BlackRook.jpg";
    ChessPieces[8] = "C:/Users/User/Desktop/BlackKnight.jpg";
    ChessPieces[9] = "C:/Users/User/Desktop/BlackBishop.jpg";
    ChessPieces[10] = "C:/Users/User/Desktop/BlackQueen.jpg";
    ChessPieces[11] = "C:/Users/User/Desktop/BlackKing.jpg";
}

void MainWindow::SetStartPosition(void)
{
    for (int i=0;i<8;i++)
        ChessPieceIndexes[i][1] = WHITE_PAWN; // White Pawns
    ChessPieceIndexes[0][0] = WHITE_ROOK; // White Rook
    ChessPieceIndexes[7][0] = WHITE_ROOK; // White Rook

    ChessPieceIndexes[1][0] = WHITE_KNIGHT; // White Knight
    ChessPieceIndexes[7][0] = WHITE_KNIGHT; // White Knight

    ChessPieceIndexes[2][0] = WHITE_BISHOP; // White Bishop
    ChessPieceIndexes[6][0] = WHITE_BISHOP; // White Bishop

    ChessPieceIndexes[3][0] = WHITE_QUEEN; // White Queen
    ChessPieceIndexes[4][0] = WHITE_KING; // White King

    for (int i=0;i<8;i++)
        ChessPieceIndexes[i][6] = BLACK_PAWN; // Black Pawns
    ChessPieceIndexes[0][7] = BLACK_ROOK; // Black Rook
    ChessPieceIndexes[7][7] = BLACK_ROOK; // Black Rook

    ChessPieceIndexes[1][7] = BLACK_KNIGHT; // Black Knight
    ChessPieceIndexes[7][7] = BLACK_KNIGHT; // Black Knight

    ChessPieceIndexes[2][7] = BLACK_BISHOP; // Black Bishop
    ChessPieceIndexes[6][7] = BLACK_BISHOP; // Black Bishop

    ChessPieceIndexes[3][7] = BLACK_QUEEN; // Black Queen
    ChessPieceIndexes[4][7] = BLACK_KING; // Black King

}


void MyGraphicsPixmapItem::mousePressEvent(QMouseEvent *eventPress)
{
    SelectedSquareX = eventPress->pos().x();
    SelectedSquareY = eventPress->pos().y();

}

[enter image description here][1]


  [1]: https://i.stack.imgur.com/XgstN.jpg

There are 3 issues which need clarification :

How do I stop the streching of the last column and row of the chess board ?
How do I make the chess pieces transparent ?
How do I implement the mouse click event so that a square gets highlighted when the user presses the left mouse button ?

SGaist

I can't tell right now
Make the original image background transparent
You can use a QRubberBand for that for exampl

Quantum1982

Thanks. I see that QGraphicsPixmapItem has a ShapeMode property. Can one set transparency with this ?

Quantum1982

Also, do you have an idea as to why the pixmap items are not being added to the scene ?

SGaist

@Quantum1982 said in Raspbian 2 player chess game:

Thanks. I see that QGraphicsPixmapItem has a ShapeMode property. Can one set transparency with this ?

If you think of MaskShape, it still mentions that the source must have an alpha channel. It's also expensive.

@Quantum1982 said in Raspbian 2 player chess game:

Also, do you have an idea as to why the pixmap items are not being added to the scene ?

Check the coordinates of your items.